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US3662996A
Expired / Lapsed
US
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Multi-chamber carburizing apparatus
Assignee: Holcroft and Co
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Filing: 1970-03-23
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Granted: 1972-05-16
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Expires: 1990-03-23
Abstract
Abstract The multi-chamber carburizing apparatus results in a continuous process including a heating furnace having inlet door means through which, when open, work is fed into the furnace, a carburizing furnace connected thereto, interconnecting double door means between the heating furnace and the carburizing furnace through which, when open, work is fed from the heating furnace into the carburizing furnace, a diffusion furnace, interconnecting double door means between the carburizing furnace and diffusion furnace through which, when open, work is fed from the carburizing furnace into the diffusion furnace, and a cooling chamber which may be a water cooled section or an oil quench tank having inlet door means through which, when open, work is fed from the diffusion furnace into the cooling chamber, or quench tank. The double door means have a space therebetween which may be filled with a neutral or other gas to act as a barrier between the furnaces. Gas passageways are provided beneath the various door means for flow of gas from the various furnaces at a controlled rate.
Inventors
- 👤 Donald J Schwalm
- 👤 Edward C Bayer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:59
CPC Classifications
C; C21; C21D; C21D1/00; C21D1/74; C23; C23C; C23C8/00; C23C8/06; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
138 words
A multi-chamber carburizing apparatus for use in a continuous carburizing process comprising a heating furnace having inlet door means through which, when open, work is fed into the furnace, a carburizing furnace connected thereto, interconnecting door means between the heating furnace and the carburizing furnace through which, when open, work is fed from the heating furnace into the carburizing furnace, and a diffusion furnace connected to the carburizing furnace, interconnecting door means between the carburizing furnace and diffusion furnace through which, when open, work is fed from the carburizing furnace into the diffusion furnace, and outlet door means on the diffusion furnace through which, when open, work is fed from the diffusion furnace, said apparatus being further characterized in that at least one of said interconnecting door means is provided with a space for a barrier gaseous atmosphere.
Claim 2
Dependent Claim
138 words
A multi-chamber carburizing apparatus for use in a continuous carburizing process comprising a heating furnace having inlet door means through which, when open, work is fed into the furnace, a carburizing furnace connected thereto, interconnecting door means between the heating furnace and the carburizing furnace through which, when open, work is fed from the heating furnace into the carburizing furnace, and a diffusion furnace connected to the carburizing furnace, interconnecting door means between the carburizing furnace and diffusion furnace through which, when open, work is fed from the carburizing furnace into the diffusion furnace, and outlet door means on the diffusion furnace through which, when open, work is fed from the diffusion furnace, said apparatus being further characterized in that at least one of said interconnecting door means is provided with a space for a barrier gaseous atmosphere.
Claim 3
Dependent Claim
40 words
Apparatus as defined in claim 1, further characterized in that each of said interconnecting door means adjacent the carburizing furnace is a double door structure having two laterally spaced door elements defining therebetween a space for a barrier gaseous atmosphere.
Claim 4
Dependent Claim
31 words
Apparatus as defined in claim 2 wherein each double door structure is provided with opening means communicating with said space for utilization alternatively as a gas inlet or a gas outlet.
Claim 5
Dependent Claim
30 words
Apparatus as defined in claim 3 wherein there is a gas passageway beneath each double door structure for communicating between the respective furnaces and the space between the door elements.
Claim 6
Dependent Claim
90 words
Apparatus as defined in claim 4, further characterized in the provision of a closed charging vestibule connected to the heating furnace and a closed discharge vestibule connected to the diffusion furnace for, respectively, receiving work for feeding into the heating furnace and for receiving finished work from the diffusion furnace, gas passageway means beneath the inlet door means for the heating furnace and the outlet door means from the diffusion furnace to provide controlled passage of gas from the furnaces to their respective vestibules, and vent means for each vestibule.
Claim 7
Dependent Claim
51 words
Apparatus as defined in claim 2 in which said door elements are pivotally connected at their upper ends to a crossbar having a vertical link within a vertical chamber for receiving said doors when raised, and means is provided operating through said link for raising and lowering the double door structure.
Claim 8
Dependent Claim
41 words
Apparatus as defined in claim 1, further characterized in the provision of another chamber connected to the outlet of the diffusion furnace, said chamber serving to cool the heated work ejected from said diffusion furnace through the aforesaid outlet door means.
Claim 9
Dependent Claim
65 words
Apparatus as defined in claim 7 wherein said cooling chamber comprises an oil quench tank, said oil quench tank being divided into a discharge vestibule directly connected to the outlet from the diffusion furnace and an outlet vestibule for discharging work from the quench tank, wall means separating said vestibules and extending into oil in the quench tank to seal the vestibules from each other.
Claim 10
Dependent Claim
35 words
Apparatus according to claim 4 in which means is provided for filling the space in at least one of said double doors with a neutral gas to create a gaseous barrier between the adjoining furnaCes.
Claim 11
Dependent Claim
27 words
Apparatus according to claim 9 in which means is provided for filling with neutral gas the spaces in both of the double doors adjacent the carburizing furnace.
Claim 12
Dependent Claim
35 words
Apparatus according to claim 4 in which means is provided for introducing generator gas into the space defined by the double door between the heating furnace and the carburizing furnace to form a gaseous barrier.
Claim 13
Independent Claim
87 words
The method of operating a multi-chamber carburizing apparatus which comprises transferring the work from a heating furnace into a carburizing furnace and then into a diffusion furnace, maintaining said furnaces at the optimum temperatures and atmospheric gaseous content by introducing neutral gas into the heating furnace, introducing generator gas plus hydrocarbon gas into the carburizing furnace, and introducing generator gas plus an oxidizing gaseous product into the diffusion furnace, and maintaining a barrier gas between said carburizing furnace and said heating furnace and said diffusion furnace, respectively.
Claim 14
Independent Claim
87 words
The method of operating a multi-chamber carburizing apparatus which comprises transferring the work from a heating furnace into a carburizing furnace and then into a diffusion furnace, maintaining said furnaces at the optimum temperatures and atmospheric gaseous content by introducing neutral gas into the heating furnace, introducing generator gas plus hydrocarbon gas into the carburizing furnace, and introducing generator gas plus an oxidizing gaseous product into the diffusion furnace, and maintaining a barrier gas between said carburizing furnace and said heating furnace and said diffusion furnace, respectively.
Claim 15
Dependent Claim
15 words
The method according to claim 12 in which the barrier gas is a neutral gas.
Claim 16
Dependent Claim
21 words
The method according to claim 12 in which the barrier gas is maintained by venting the gas from the carburizing furnace.
Claim 17
Dependent Claim
39 words
The method according to claim 12 in which barrier gases are maintained at the entrance to the heating furnace and the exit from the diffusion furnace by venting thereinto the gases for said heating and said diffusion furnaces, respectively.
Claim 18
Dependent Claim
19 words
The method according to claim 15 in which the barrier gas adjacent the carburizing furnace is a neutral gas.
Claim 19
Dependent Claim
24 words
The method according to claim 15 wherein the barrier gas adjacent the carburizing furnace is maintained by venting the gas from said carburizing furnace.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-16 | 1975-11-15 | 1976-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-16 | 1979-11-15 | 1980-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-16 | 1983-11-15 | 1984-05-16 | $7700.00 | Window Closed / Lapsed |